Incidental Gallbladder Carcinoma

Abstract

Gallbladder cancer (GBC) is a rare yet fatal disease with poor prognosis of reported less than 5% in 5-year survival. Incidental GBC is discovered following 0.25–3.0% of laparoscopic cholecystectomies. This constitutes a majority of GBC diagnoses (50–70%). Incidental GBC is generally diagnosed at an earlier stage and carries a better prognosis than non-incidental GBC. Risks of incidental GBC have increased in the following conditions: conversion of laparoscopic cholecystectomy to open cholecystectomy, advanced age (≥65 years old), Asian or African-American race, an elevated alkaline phosphatase level (≥120 units/L), and female sex. Other risk factors also include previous cholecystitis, bilirubin level, and the presence of acute cholecystitis. Preoperative diagnosis of incidental GBC is difficult in clinical practice as there is no mass seen on preoperative imaging, and cholecystectomy is performed for presumed benign stone disease. For the suspicious wall thickening of gallbladder, routine use of elastography during ultrasonography combined with MDCT may assist in the earlier discovery of incidental GBC. Therapy can be multimodal yet surgical intervention is the mainstay of GBC treatment. A simple cholecystectomy is adequate for GBC contained within mucosa (Tis, T1a). For T1b and above, reoperation for incidental GBC should have two fundamental objectives: R0 resection and clearance of the locoregional lymph nodes. Utmost care to prevent bile spillage and gallbladder perforation is indisputably necessary during operation. Gallbladder cancer predictive risk score (GBRS) has been proposed to determine the probability of residual disease based on T-stage, tumor differentiation, lymphovascular invasion (LVI), and perineural invasion (PNI). With further validation in a larger population, GBRS may prove to be a great tool in optimizing treatment strategy. The role of an adjuvant therapy needs further investigation in better detail and for subgroups. Until then, adjuvant capecitabine seems to improve oncologic outcomes.